Preparation method of biomimetic degradable, controlled-release lubricant polyurethane marine antifouling coating

Abstract

The invention discloses a preparation method of a biomimetic degradable and controlled-release lubricant polyurethane marine antifouling coating, which is characterized by comprising the following steps: S1: dispersing 0.1-3 g of silicon dioxide, 1.2-25 g of lubricant and 0.5-5 g of γ-aminopropyltriethoxysilane in 20-50 mL of an organic solvent, and magnetically stirring for 10-15 hours at room temperature to obtain a mixed solution A; S2: adding 5-10 g of diol A and 0.5-5 g of diol B into a four-necked flask, introducing inert gas protection, and then dropwise adding 2-10 g of diisocyanate under mechanical stirring. Mix evenly at 40°C, reflux at 70°C for 2h to complete the prepolymerization and obtain mixed solution B; S3: reduce the temperature of mixed solution B to 60°C, add 0.2~2g of chain extender and mixed solution A to obtain mixed solution C, and drop 2~3 drops of dibutyltin dilaurate, react for 2h to obtain mixed solution D; S4: reduce the temperature of mixed solution D to 40°C, add 0.15~1.5g of triethylamine, react for 10min, then add 50~100mL of deionized water for demulsification, the demulsification time is 1h, and a uniform milky white polyurethane emulsion is obtained, which is then sprayed on the substrate.

Description

Technical Field

[0001] The invention belongs to the technical field of functional antifouling coatings, and in particular relates to a method for preparing a biomimetic degradable, controlled-release lubricating oil polyurethane marine antifouling coating. Background Art

[0002] Marine biofouling can lead to increased fuel consumption and greenhouse gas emissions from ships, while also accelerating corrosion on the surface of marine equipment and significantly shortening its service life. The use of antifouling coatings is currently the most effective and economical way to prevent and control marine biofouling. Traditional antifouling coatings achieve antifouling by releasing heavy metals such as copper, tin, mercury, and lead. The use of these antifouling agents will have an adverse impact on the marine ecological environment. Currently, the self-polishing antifouling coatings used have good antifouling effects due to the self-renewal of the surface, but they also contain antifouling agents, which is not in line with the concept of environmental protection. On the other hand, lubricant-infused porous surface (SLIPS) coatings have recently attracted widespread attention from researchers, but the rapid loss of lubricant leads to unstable antifouling effects of the coatings and shortens the service life of the coatings.

[0003] Therefore, in response to some of the shortcomings of current antifouling coatings, designing a coating that does not contain antifouling agents and controls the release of lubricating oil through material degradation to achieve an environmentally friendly, efficient and anti-biological adhesion marine antifouling coating is a technical problem that needs to be urgently solved by relevant technical personnel in the industry. Summary of the Invention

[0004] To address these issues, the present invention proposes a method for preparing a biomimetic, biodegradable, controlled-release lubricant polyurethane marine antifouling coating, inspired by the self-cleaning mucus secreted by marine organisms. Leveraging the hydrolyzable nature of the ester group, the coating achieves surface self-renewal while continuously exuding lubricant to deceive biorecognition and further reduce bioadhesion. This coating overcomes the challenges of environmental pollution caused by antifouling agents and the rapid loss of lubricant.

[0005] A method for preparing a biomimetic biodegradable, controlled-release lubricant polyurethane marine antifouling coating comprises the following steps:

[0006] S1: Disperse 0.1-3 g of silica, 1.2-25 g of lubricating oil, and 0.5-5 g of γ-aminopropyltriethoxysilane (KH-550) in 20-50 mL of an organic solvent and stir magnetically at room temperature for 10-15 h to obtain a mixed solution A.

[0007] S2: Add 5-10g of diol A (diol A does not contain an ester group) and 0.5-5g of diol B (diol B contains an ester group) into a four-necked flask, introduce inert gas, then add 2-10g of diisocyanate dropwise under mechanical stirring and mix thoroughly. Reflux at 70°C for 2h to complete prepolymerization and obtain mixed solution B.

[0008] S3: Lower the temperature of mixed solution B to 60°C, add 0.2-2 g of chain extender and mixed solution A to obtain mixed solution C, and then add 2-3 drops of dibutyltin dilaurate (DBTDL) and react for 2 h to obtain mixed solution D.

[0009] S4: Lower the temperature of mixed solution D to 40°C, add 0.15-1.5g of triethylamine (TEA), react for 10 minutes, then add 50-100mL of deionized water to break the emulsion. The breaking time is 1 hour to obtain a uniform milky white polyurethane emulsion, which is then sprayed on the substrate.

[0010] Furthermore, in S2, if diol A and diol B are solid structures, they need to be dissolved in acetone.

[0011] Furthermore, the lubricant in S1 can be selected from but not limited to the following: silicone oil, linseed oil, and soybean oil.

[0012] Furthermore, the diol A in S2 can be selected from but not limited to the following: polytetramethylene ether glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene oxide-propylene glycol copolymer.

[0013] Furthermore, the diol B in S2 can be selected from but not limited to the following: polycaprolactone diol, polylactic acid diol.

[0014] Furthermore, the diisocyanate in S2 can be selected from but not limited to the following: isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, and 2,2,4-trimethylhexane diisocyanate.

[0015] Furthermore, the chain extender in S3 can be selected from but not limited to the following: 2,2-dihydroxymethylpropionic acid (DMPA) and 2,2-dihydroxymethylbutanoic acid (DMBA).

[0016] Furthermore, the spraying method in S4 is to spray from left to right and from top to bottom, the air pressure of the air compressor is controlled below 1 bar, the spray gun angle is 45 degrees, and the distance between the spray gun and the substrate is 15 to 25 cm.

[0017] Beneficial effects of the present invention:

[0018] The chemical composition of the coating prepared in the example was characterized by Fourier transform infrared spectroscopy, verifying the successful preparation of the polyurethane. Antibacterial results showed that compared with the pure substrate, the antibacterial adhesion rate of the biomimetic degradable, controlled-release lubricant polyurethane marine antifouling coating reached over 90%. Furthermore, compared with pure polyurethane, the coating exhibited excellent resistance to Chlorella adhesion. The biomimetic degradable, controlled-release lubricant polyurethane marine antifouling coating has mild synthesis conditions, enabling large-scale production. At the same time, the coating exhibits excellent anti-biofouling properties and can be used for antifouling of marine equipment.

[0019] This biomimetic, biodegradable, controlled-release lubricant polyurethane marine antifouling coating, based on the hydrolysis reaction of ester groups contained in diols, achieves self-renewal of the coating surface while continuously releasing lubricant, further reducing bioadhesion on the coating surface. The marine antifouling coating prepared by this invention features simple synthesis and excellent film-forming properties. It requires minimal substrate preparation and exhibits excellent adhesion, a low curing temperature, and the ability to be manufactured on a large scale. It is suitable for use in protecting marine equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 The infrared spectra of the coatings prepared in Examples 1-3;

[0022] Figure 2 Antibacterial test diagrams of pure substrate (aluminum alloy) and coatings prepared in Examples 1-3;

[0023] Figure 3 Graph showing the 30-day anti-algae test of pure polyurethane (WPUD) and the coatings prepared in Examples 1-3. DETAILED DESCRIPTION

[0024] The technical solutions of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included within the scope of protection intended by the present invention.

[0025] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0026] Embodiment 1 of the present invention

[0027] A method for preparing a biomimetic biodegradable, controlled-release lubricant polyurethane marine antifouling coating comprises the following steps:

[0028] S1: Disperse 0.5 g of silica, 1.5 g of silicone oil, and 2.5 g of γ-aminopropyltriethoxysilane (KH-550) in 30 mL of organic solvent and magnetically stir at room temperature for 12 h to obtain a mixture A.

[0029] S2: Dissolve 9.15 g of polypropylene glycol and 2.15 g of polycaprolactone diol in 20 mL of acetone and add them together to a four-necked flask. Pass an inert gas into the flask, then add 5.55 g of isophorone diisocyanate dropwise and mix well under mechanical stirring. Set the water bath temperature to 70°C and reflux for 2 h to complete the prepolymerization to obtain mixed solution B.

[0030] S3: Lower the water bath temperature to 60°C, add 0.94 g of 2,2-dihydroxymethylpropionic acid (DMPA) and mixture A to mixture B to prepare mixture C, and add 3 drops of dibutyltin dilaurate (DBTDL) and react for 2 h to obtain mixture D.

[0031] S4: Lower the water bath temperature to 40°C, add 0.7 g of triethylamine (TEA) to the mixture D, react for 10 minutes, and then add 75 mL of deionized water to break the emulsion. The breaking time is 1 hour to obtain a uniform milky white polyurethane emulsion. Then, spray the treated substrate.

[0032] Embodiment 2 of the present invention

[0033] A method for preparing a biomimetic biodegradable, controlled-release lubricant polyurethane marine antifouling coating comprises the following steps:

[0034] S1: Disperse 1 g of silica, 5 g of silicone oil, and 2.5 g of γ-aminopropyltriethoxysilane (KH-550) in 30 mL of an organic solvent and magnetically stir at room temperature for 12 h to obtain a mixture A.

[0035] S2: Dissolve 9.15 g of polypropylene glycol and 2.15 g of polycaprolactone diol in 20 mL of acetone and add them together to a four-necked flask. Pass an inert gas into the flask, then add 5.55 g of isophorone diisocyanate dropwise and mix well under mechanical stirring. Set the water bath temperature to 70°C and reflux for 2 h to complete the prepolymerization to obtain mixed solution B.

[0036] S3: Lower the water bath temperature to 60°C, add 0.94 g of 2,2-dihydroxymethylpropionic acid (DMPA) and mixture A to mixture B to prepare mixture C, and add 3 drops of dibutyltin dilaurate (DBTDL) and react for 2 h to obtain mixture D.

[0037] S4: Lower the water bath temperature to 40°C, add 0.7 g of triethylamine (TEA) to the mixture D, react for 10 minutes, and then add 75 mL of deionized water to break the emulsion. The breaking time is 1 hour to obtain a uniform milky white polyurethane emulsion. Then, spray the treated substrate.

[0038] Embodiment 3 of the present invention

[0039] A method for preparing a biomimetic biodegradable, controlled-release lubricant polyurethane marine antifouling coating comprises the following steps:

[0040] S1: Disperse 1.5 g of silica, 15 g of silicone oil, and 3.7 g of γ-aminopropyltriethoxysilane (KH-550) in 30 mL of organic solvent and magnetically stir at room temperature for 14 h to obtain a mixture A.

[0041] S2: Dissolve 9.15 g of polypropylene glycol and 2.15 g of polycaprolactone diol in 20 mL of acetone and add them together to a four-necked flask. Pass an inert gas into the flask, then add 5.55 g of isophorone diisocyanate dropwise and mix well under mechanical stirring. Set the water bath temperature to 70°C and reflux for 2 h to complete the prepolymerization to obtain mixed solution B.

[0042] S3: Lower the water bath temperature to 60°C, add 0.94 g of 2,2-dihydroxymethylpropionic acid (DMPA) and mixture A to mixture B to prepare mixture C, and add 3 drops of dibutyltin dilaurate (DBTDL) and react for 2 h to obtain mixture D.

[0043] S4: Lower the water bath temperature to 40°C, add 0.7 g of triethylamine (TEA) to the mixture D, react for 10 minutes, and then add 75 mL of deionized water to break the emulsion. The breaking time is 1 hour to obtain a uniform milky white polyurethane emulsion. Then, spray the treated substrate.

[0044] The chemical composition of the coatings prepared in Examples 1-3 was characterized by Fourier transform infrared spectroscopy (FTIR), verifying the successful preparation of the polyurethane. Antibacterial results showed that the biomimetic, biodegradable, controlled-release lubricant polyurethane marine antifouling coating achieved an antibacterial adhesion rate exceeding 90% compared to the pure substrate. Furthermore, compared to pure polyurethane, the coating exhibited excellent resistance to Chlorella vulgaris adhesion. The biomimetic, biodegradable, controlled-release lubricant polyurethane marine antifouling coating is synthesized under mild conditions, enabling large-scale production. Furthermore, the coating exhibits excellent anti-biofouling properties, making it suitable for antifouling applications in marine equipment.

[0045] The above is an exemplary description of the embodiments of the present invention. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A method for preparing a biomimetic, biodegradable, controlled-release lubricant polyurethane marine antifouling coating, characterized by: The steps include: S1: Disperse 0.1-3 g of silica, 1.2-25 g of lubricating oil, and 0.5-5 g of γ-aminopropyltriethoxysilane in 20-50 mL of an organic solvent, and magnetically stir at room temperature for 10-15 h to obtain a mixed solution A; S2: Add 5-10g of diol A and 0.5-5g of diol B into a four-necked flask, introduce inert gas, then add 2-10g of diisocyanate dropwise under mechanical stirring and mix well. Reflux at 70°C for 2h to complete prepolymerization and obtain mixed solution B. S3: Lower the temperature of mixed solution B to 60°C, add 0.2-2 g of chain extender and mixed solution A to obtain mixed solution C, and then add 2-3 drops of dibutyltin dilaurate. React for 2 h to obtain mixed solution D. S4: Lower the temperature of the mixed solution D to 40°C, add 0.15-1.5g of triethylamine, react for 10 minutes, then add 50-100mL of deionized water to break the emulsion. The breaking time is 1 hour to obtain a uniform milky white polyurethane emulsion, which is then sprayed on the substrate; The diol A in S2 is a diol without an ester group; the diol B in S2 is a diol with an ester group.

2. The method for preparing the biomimetic degradable, controlled-release lubricant polyurethane marine antifouling coating according to claim 1, characterized in that: The spraying method in S4 is to spray from left to right and from top to bottom, the air pressure of the air compressor is controlled below 1 bar, the spray gun angle is 45 degrees, and the distance between the spray gun and the substrate is 15 to 25 cm.

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